ΔE 7.1, close: similar, with a visible difference side by side. Iridescent Purple/Green is more muted, warmer than Augur Blue. They are different kinds of paint: Army Painter Augur Blue is an opaque base/layer paint and Tamiya Iridescent Purple/Green is a pearl paint, so they won’t behave the same on the model even where the colour is close.
Usually, if you are not matching paint already on the model. Close match (ΔE 7). Iridescent Purple/Green is more muted, warmer than Augur Blue. They are different kinds of paint.
The same difference applies the other way round: Augur Blue is more saturated, cooler.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Augur Blue on the colour wheel See Iridescent Purple/Green on the colour wheel
All matches: Augur Blue equivalents · Iridescent Purple/Green equivalents